First experimental evidence of the piezoelectric nature of struvite.

In this paper, we present the first experimental evidence of the piezoelectric nature of struvite (MgNHPO·6HO). Using a single diffusion gel growth technique, we have grown struvite crystals in the form of plane parallel plates. For struvite crystals of this shape, we measured the piezoelectric coefficients d and d.

The Anti-Proliferative Activity of Coordination Compound-Based ZnO Nanoparticles as a Promising Agent Against Triple Negative Breast Cancer Cells.

Purpose: The present study deals with the in vitro evaluation of the potential use of coordination compound-based zinc oxide (ZnO) nanoparticles (NPs) for the treatment of triple negative breast cancer cells (TNBrCa). As BrCa is one of the most prevalent cancer types and TNBrCa treatment is difficult due to poor prognosis and a high metastasis rate, finding a more reliable treatment option should be of the utmost interest.

Methods: Prepared by reacting zinc carboxylates (formate, acetate, propionate, butyrate, isobutyrate, valerate) and hexamethylenetetramine, 4 distinct coordination compounds were further subjected to two modes of conversion into ZnO NPs - ultrasonication with oleic acid or heating of pure precursors in an air atmosphere.

Influence of n-ZnO Morphology on Sulfur Crosslinking and Properties of Styrene-Butadiene Rubber Vulcanizates.

This paper examines the influence of the morphology of zinc oxide nanoparticles (n-ZnO) on the activation energy, vulcanization parameters, crosslink density, crosslink structure, and mechanical properties in the extension of the sulfur vulcanizates of styrene-butadiene rubber (SBR). Scanning electron microscopy was used to determine the particle size distribution and morphology, whereas the specific surface area (SSA) and squalene wettability of the n-ZnO nanoparticles were adequately evaluated using the Brunauer-Emmet-Teller (BET) equation and tensiometry. The n-ZnO were then added to the SBR in conventional (CV) or efficient (EV) vulcanization systems.

Molecular self-assembly of 1D infinite polyiodide helices in a phenanthrolinium salt.

A new linear polymeric polyiodide, catena-poly[tris(1,10-phenanthrolin-1-ium)tris(1,10-phenanthroline)heptaiodide], was prepared by one-step synthesis. Its formation is driven by hydrogen-bond assisted supramolecular assembly in the presence of chromium(iii) acetate. Its structure has been characterized by the means of single-crystal X-ray diffraction.

Physicochemical Insight into Coordination Systems Obtained from Copper(II) Bromoacetate and 1,10-Phenanthroline.

Two different coordination compounds of copper were synthesized from the same building blocks (1,10-phenanthroline, bromoacetate anions, and copper cations). The synthesis parameters were carefully designed and evaluated to allow the change of the resulting compounds molecular structure, i.e.

Dinuclear uranium(VI) salen coordination compound: an efficient visible-light-active catalyst for selective reduction of CO to methanol.

A new dinuclear uranyl salen coordination compound, [(UO2)2(L)2]·2MeCN [L = 6,6'-((1E,1'E)-((2,2-dimethylpropane-1,3-diyl)bis(azaneylylidene))-bis(methaneylylidene))bis(2-methoxyphenol)], was synthesized using a multifunctional salen ligand to harvest visible light for the selective photocatalytic reduction of CO2 to MeOH. The assembling of the two U centers into one coordination moiety via a chelating-bridging doubly deprotonated tetradentate ligand allowed the formation of U centers with distorted pentagonal bipyramid geometry. Such construction of compounds leads to excellent activity for the photocatalytic reduction of CO2, permitting a production rate of 1.

Structural and Theoretical Investigations, Hirshfeld Surface Analyses, and Cytotoxicity of a Naphthalene-Based Chiral Compound.

A novel Schiff base compound derived from the condensation of 2-hydroxy-1-naphthaldehyde with (1,2)-(-)-1,2-diphenylethylenediamine in 2:1 M ratio was reported and investigated by elemental analyses, Fourier transform infrared and NMR spectroscopic studies, and single-crystal X-ray crystallography. Hirshfeld surface analyses were also carried out to measure the various intermolecular contacts controlling the supramolecular topology, suggesting the H···O (7.6%) contacts to be the most significant interactions, whereas the H···H (48.

Five new complexes with deferiprone and N,N-donor ligands: evaluation of cytotoxicity against breast cancer MCF-7 cell line and HSA-binding determination.

In this study, five new complexes containing deferiprone (dfp) and N,N-donor ligands [bipyridine (bpy), 1,10-phenanthroline (phen) and ethylenediamine (en)] were synthesized: [Fe(dfp)(bpy)](PF) (), [Fe(dfp)(phen)](PF) (), [Cu(dfp)(bpy)](PF) (), [Ga(dfp)(bpy)](PF) (), and [Fe(dfp)(en)](PF) (). Characterization of these complexes was carried out through elemental analysis and FT-IR, and single-crystal X-ray crystallography was used to determine their structures. Whilst the polyhedron has a distorted octahedral geometry in , , , and , it adopts a distorted square-pyramidal geometry in .

1,3,4-Thiadiazole-Containing Azo Dyes: Synthesis, Spectroscopic Properties and Molecular Structure.

Three series of azo dyes derived from 2-amino-5-aryl-1,3,4-thiadiazoles and aniline, -dimethylaniline and phenol were synthesized in high yields by a conventional diazotization-coupling sequence. The chemical structures of the prepared compounds were confirmed by H-NMR, C-NMR, IR, UV-Vis spectroscopy, mass spectrometry and elemental analysis. In addition, the X-ray single crystal structure of a representative azo dye was presented.

Photoluminescence enhancement of Re(i) carbonyl complexes bearing D-A and D-π-A ligands.

Three Re(i) carbonyl complexes [ReCl(CO)3(Ln)] bearing 2,2'-bipyridine, 2,2':6',2''-terpyridine, and 1,10-phenanthroline functionalized with diphenylamine/or triphenylamine units (L1-L3) were synthesized to explore the impact of highly electron donating units appended to the imine ligand on the thermal and optoelectronic properties of Re(i) systems. Additionally, for comparison, the ligands L1-3 and parent complexes [ReCl(CO)3(bipy)], [ReCl(CO)3(phen)] and [ReCl(CO)3(terpy-κ2N)] were investigated. The thermal stability was evaluated by differential scanning calorimetry.

Interplay between Polymorphism and Isostructurality in the 2-Fur- and 2-Thenaldehyde Semi- and Thiosemicarbazones.

The four compounds, namely: 5-nitro-2-furaldehyde thiosemicarbazone (); 5-nitro-2-thiophene thiosemicarbazone (); 5-nitro-2-furaldehyde semicarbazone (); and 5-nitro-2-thiophene semicarbazone () were synthesized and crystallized. The three new crystal structures of , , and were determined and compared to three already known crystal structures of . Additionally, two new polymorphic forms of solvate were synthesized and studied.

Copper(I) complexes with phosphines P(p-OCH-Ph)CHOH and P(p-OCH-Ph)CHSarGly. Synthesis, multimodal DNA interactions, and prooxidative and in vitro antiproliferative activity.

Phosphonium salt (p-OCH-Ph)P(CHOH)Cl (MPOHC), derived phosphine ligands without and with SarGly (Sarcosine-Glycine) peptide carrier P(p-OCH-Ph)CHOH (MPOH) and P(p-OCH-Ph)CHSarGly (MPSG), respectively, and two copper(I) complexes [Cu(I)(dmp)(MPOH)] (1-MPOH; dmp = (2,9-dimethyl-1,10-phenanthroline)) and [Cu(I)(dmp)(MPSG)] (1-MPSG) were synthesized. The resulting compounds were characterized by elemental analysis, 1D and 2D NMR and UV-Vis absorption spectroscopies, mass spectrometry, cyclic voltammetry and by X-ray diffraction analysis. Cytotoxicity of all compounds was evaluated in vitro against colon, lung, breast, pancreatic, prostate tumor cell lines, as well as towards non-tumor cell lines: lung, kidney and keratinocyte.

Influence of the pyrazine substituent on the structure and magnetic properties of dicyanamide-bridged cobalt(ii) complexes.

Substituted pyrazines were successfully used to prepare two new coordination polymers of formulas {[Co(dca)2(NH2pyz)2]·H2O}n (1) and [Co3(dca)6(HOpyz)5(H2O)2]n (2) [dca = dicyanamide, NH2pyz = 2-aminopyrazine and HOpyz = 2-hydroxypyrazine] whose structures were determined by single-crystal X-ray crystallography. The structure of 1 consists of a two-dimensional rhombus grid of cobalt(ii) ions where the dca ligand adopts the μ1,5 bridging mode with trans-positioned monodentate NH2pyz molecules completing the six-coordination around each metal ion. Compound 2 exhibits a stair-like two-dimensional structure where the intralayer connections are performed by the dca and HOpyz groups exhibiting μ1,5 and bis-monodentate coordination modes, respectively.

Structural Insights into Influence of Isomerism on Properties of Open Shell Cobalt Coordination System.

The two coordination compounds of cobalt were designed and synthesized. The substrates were carefully selected to allow gentle tuning of the molecular structure of the designed compounds. The crystal, molecular and supramolecular structure of studied compounds has been determined and discussed.

Copper(ii) complexes with 2,2':6',2''-terpyridine, 2,6-di(thiazol-2-yl)pyridine and 2,6-di(pyrazin-2-yl)pyridine substituted with quinolines. Synthesis, structure, antiproliferative activity, and catalytic activity in the oxidation of alkanes and alcohols with peroxides.

A series of 2,2':6',2''-terpyridine (terpy), 2,6-di(thiazol-2-yl)pyridine (dtpy) and 2,6-di(pyrazin-2-yl)pyridine (dppy) derivatives with n-quinolyl substituents (n = 2 and 4) was used to synthesize five-coordinate complexes [CuCl(n-quinolyl-terpy)] (1-2), [CuCl(n-quinolyl-dtpy)] (3-4) and [CuCl(n-quinolyl-dppy)] (5-6), respectively. The main emphasis of the research was to investigate the impact of the triimine skeleton (terpy, dtpy and dppy) and n-quinolyl pendant substituent on the antiproliferative and catalytic properties of 1-6. The obtained Cu(ii) compounds were studied as antiproliferative agents against human colorectal (HCT116) and ovarian (A2780) carcinoma, and they were used as catalysts for the oxidation of alkanes and alcohols with peroxides under mild conditions.

Synthesis of 4-Alkyl-4-1,2,4-triazole Derivatives by Suzuki Cross-coupling Reactions and Their Luminescence Properties.

New derivatives of 4-alkyl-3,5-diaryl-4-1,2,4-triazole were synthesized utilizing the Suzuki cross-coupling reaction. The presented methodology comprises of the preparation of bromine-containing 4-alkyl-4-1,2,4-triazoles and their coupling with different commercially available boronic acids in the presence of ionic liquids or in conventional solvents. The obtained compounds were tested for their luminescence properties.

Folic acid-mediated re-shuttling of ferritin receptor specificity towards a selective delivery of highly cytotoxic nickel(II) coordination compounds.

Metal-based coordination compounds, including the well-known cytostatic drug cisplatin, are widely used in the anticancer therapy. Generally, they exhibit high cytotoxicity not only towards malignant cells, but also towards non-malignant cells, which represents main problem of their clinical use. Herein, we describe the synthesis, characterization and biological testing of three trinuclear nickel(II) coordination compounds.

Synthesis and structural characterization of antimicrobial binuclear copper(II) coordination compounds bridged by hydroxy- and/or thiodipropionic acid.

In the present study, two binuclear copper(II) coordination compounds bridged by hydroxy- and thiodipropionic acid have been synthesized. The structure of compounds was determined by X-ray crystallography. The central copper atoms exist in square pyramidal surroundings.

New fluorescent compounds based on zinc thiocyanate: influence of structure on spectral properties.

New coordination compounds based on zinc thiocyanate, namely (acetone thiosemicarbazone-κN,S)bis(isothiocyanato-κN)zinc(II) monohydrate, [Zn(NCS)(CHNS)]·HO, (I), and diaquatetrakis(urea-κO)zinc(II) tetrakis(isothiocyanato-κN)zinc(II), [Zn(CHNO)(HO)][Zn(NCS)], (II), were synthesized and studied by UV-Vis, fluorescence and IR spectroscopy. Coordination salt (II) forms a rare system composed of two different coordination units of the same metal and it is the first example of a compound with two completely different zinc coordination units, of which one contains a tetrakis(urea)zinc unit. Both (I) and (II) possess fluorescence properties and produce blue and green emissions, respectively, upon irradiation with violet light.

A (salicylaldiminato)Pt(II) complex with dimethylpropylene linkage: Synthesis, structural characterization and antineoplastic activity.

A novel (salicylaldiminato)Pt(II) complex with two different molecular structures, one solventless ((salicylaldiminato)Pt(II)) 1 and another one solvated ((salicylaldiminato)Pt(II). CHOH), 1·CHOH, has been obtained by the reaction of a salen ligand with [PtCl(DMSO)] in ethanol at room temperature. The asymmetric unit of solventless 1 contains 9 such complex molecules whereas 1·CHOH contains 2 complex molecules and one ethanol molecule.

Synthesis and activity of opioid peptidomimetics with β- and β-amino acids.

Morphiceptin (Tyr-Pro-Phe-Pro-NH) is a selective ligand of the mu opioid receptor, an important target in pain regulation. In this study, morphiceptin was modified at positions 2 or 3 by introduction of β- or β-amino acids and additionally in position 1 by replacing Tyr by Dmt (2',6'-dimethyltyrosine), which resulted in obtaining enzymatically stable analogs with mixed opioid receptor affinity profiles. An analog of the sequence Dmt-d-Ala-(R)-β-1-Nal-Pro-NH [Nal=3-(1-naphthyl)-alanine] showed very high activity at the mu and delta receptors in the calcium mobilization functional test but did not cross the artificial membrane imitating the blood-brain barrier.

Spin Crossover in Double Salts Containing Six- and Four-Coordinate Cobalt(II) Ions.

The preparation and spectroscopic and structural characterization of three cobalt(II) complexes of formulas [Co(tppz)](dca) (1), [Co(tppz)][Co(NCS)]·MeOH (2), and [Co(tppz)][Co(NCO)]·2HO (3) [tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine and dca = dicyanamide] are reported here. Compounds 1-3 have in common the presence of the cationic [Co(tppz)] entity where each mer-tridentate tppz ligand coordinates to the cobalt(II) ion equatorially through two pyridyl donors and axially via the pyrazine, completing the six-coordination. The electroneutrality is achieved by the organic dca group (1) and the anionic tetrakis(thiocyanato-κN)cobaltate(II) (2) and tetrakis(cyanato-κN)cobaltate(II) (3) complexes.

Characterization and cytotoxic effect of aqua-(2,2',2''-nitrilotriacetato)-oxo-vanadium salts on human osteosarcoma cells.

The use of protonated N-heterocyclic compound, i.e. 2,2'-bipyridinium cation, [bpyH], enabled to obtain the new nitrilotriacetate oxidovanadium(IV) salt of the stoichiometry [bpyH][VO(nta)(HO)]HO.

Structural elucidation and physicochemical properties of mononuclear Uranyl(VI) complexes incorporating dianionic units.

Two derivatives of organouranyl mononuclear complexes [UO2(L)THF] (1) and [UO2(L)Alc] (2), where L = (2,2'-(1E,1'E)-(2,2-dimethylpropane-1,3-dyl)bis(azanylylidene, THF = Tetrahydrofuran, Alc = Alcohol), have been prepared. These complexes have been determined by elemental analyses, single crystal X-ray crystallography and various spectroscopic studies. Moreover, the structure of these complexes have also been studied by DFT and time dependent DFT measurements showing that both the complexes have distorted pentagonal bipyramidal environment around uranyl ion.